Preparation and Liquid Crystalline Behaviour of a Series of Semifluorinated Allylic Monomers

A series of smectic liquid-crystalline 4,4′-biphenyl derivatives incorporating a perfluorinated segment and an allylic part have been prepared and their mesomorphic properties investigated. The preparation of these compounds has been done from 2-F-butylethyl iodide, the 2-F-hexylethyl iodide or the 2-F-octylpropanoic acid. The physical properties of these novel fluorinated materials are commented and illustrated in comparison with four homologous allylic series previously described. The choice of the molecular design of these monomers allows us to obtain dimorphism and high mesomorphic range determined from differential thermal analysis and the light microscopy.

Keywords:

• dimorphism
• fluorinated
• molecular design
• smectic

Acknowledgments

The authors thank Atofina for the gift of perfluoroalkylated raw materials. LC thanks MENRT for a grant.

Notes

C, crystal, S_A, S_E: Smectic A and E respectively, I, isotropic.